Nuclear Structure and Reactions: Theory and Experiment
Lead Research Organisation:
University of Surrey
Department Name: Physics
Abstract
Nuclear physics research is undergoing a transformation. For a hundred years, atomic nuclei have been probed by collisions between stable beams and stable targets, with just a small number of radioactive isotopes being available. Now, building on steady progress over the past 20 years, it is at last becoming possible to generate intense beams of a wide range of short-lived isotopes, so-called "radioactive beams". This enables us vastly to expand the scope of experimental nuclear research. For example, it is now realistic to plan to study in the laboratory a range of nuclear reactions that take place in exploding stars. Thereby, we will be able to understand how the chemical elements that we find on Earth were formed and distributed through the Universe.
At the core of our experimental research is our strong participation at leading international radioactive-beam facilities. While we are now contributing, or planning to contribute, to substantial technical developments at these facilities, the present grant request is focused on the exploitation of the capabilities that are now becoming available.
Experimental progress is intimately linked with theory, where novel and practical approaches are a hallmark of the Surrey group. An outstanding feature, which is key to our group's research plans and is unique in the UK, is our powerful blend of theoretical and experimental capability.
Our science goals are aligned with current STFC strategy for nuclear physics, as expressed in detail through the Nuclear Physics Advisory Panel. We wish to understand the boundaries of nuclear existence, i.e. the limiting conditions that enable neutrons and protons to bind together to form nuclei. Under such conditions, the nuclear system is in a delicate state and shows unusual phenomena. It is very sensitive to the properties of the nuclear force. For example, weakly bound neutrons can orbit their parent nucleus at remarkably large distances. This is already known, and our group made key contributions to this knowledge. What is unknown is whether, and to what extent, the neutrons and protons can show different collective behaviours. Also unknown, for most elements, is how many neutrons can bind to a given number of protons. It is features such as these that determine how stars explode. To tackle these problems, we need a more sophisticated understanding of the nuclear force, and we need experimental information about nuclei with unusual combinations of neutrons and protons to test our theoretical ideas and models. Therefore, theory and experiment go hand-in-hand as we push forward towards the nuclear limits.
An overview of nuclear binding reveals that about one half of predicted nuclei have never been observed, and the vast majority of this unknown territory involves nuclei with an excess of neutrons. Much of our activity addresses this "neutron-rich" territory, exploiting the new capabilities with radioactive beams.
Our principal motivation is the basic science, and we contribute strongly to the world sum of knowledge and understanding. Nevertheless, there are more-tangible benefits. For example, our radiation-detector advances can be incorporated in medical diagnosis and treatment. In addition, we provide an excellent training environment for our research students and staff, many of whom go on to work in the nuclear power industry, helping to fill the current skills gap. On a more adventurous note, our special interest in nuclear isomers (energy traps) could lead to novel energy applications. Furthermore, we have a keen interest in sharing our specialist knowledge with a wide audience, and we already have an enviable track record with the media.
At the core of our experimental research is our strong participation at leading international radioactive-beam facilities. While we are now contributing, or planning to contribute, to substantial technical developments at these facilities, the present grant request is focused on the exploitation of the capabilities that are now becoming available.
Experimental progress is intimately linked with theory, where novel and practical approaches are a hallmark of the Surrey group. An outstanding feature, which is key to our group's research plans and is unique in the UK, is our powerful blend of theoretical and experimental capability.
Our science goals are aligned with current STFC strategy for nuclear physics, as expressed in detail through the Nuclear Physics Advisory Panel. We wish to understand the boundaries of nuclear existence, i.e. the limiting conditions that enable neutrons and protons to bind together to form nuclei. Under such conditions, the nuclear system is in a delicate state and shows unusual phenomena. It is very sensitive to the properties of the nuclear force. For example, weakly bound neutrons can orbit their parent nucleus at remarkably large distances. This is already known, and our group made key contributions to this knowledge. What is unknown is whether, and to what extent, the neutrons and protons can show different collective behaviours. Also unknown, for most elements, is how many neutrons can bind to a given number of protons. It is features such as these that determine how stars explode. To tackle these problems, we need a more sophisticated understanding of the nuclear force, and we need experimental information about nuclei with unusual combinations of neutrons and protons to test our theoretical ideas and models. Therefore, theory and experiment go hand-in-hand as we push forward towards the nuclear limits.
An overview of nuclear binding reveals that about one half of predicted nuclei have never been observed, and the vast majority of this unknown territory involves nuclei with an excess of neutrons. Much of our activity addresses this "neutron-rich" territory, exploiting the new capabilities with radioactive beams.
Our principal motivation is the basic science, and we contribute strongly to the world sum of knowledge and understanding. Nevertheless, there are more-tangible benefits. For example, our radiation-detector advances can be incorporated in medical diagnosis and treatment. In addition, we provide an excellent training environment for our research students and staff, many of whom go on to work in the nuclear power industry, helping to fill the current skills gap. On a more adventurous note, our special interest in nuclear isomers (energy traps) could lead to novel energy applications. Furthermore, we have a keen interest in sharing our specialist knowledge with a wide audience, and we already have an enviable track record with the media.
Planned Impact
Here we address more specifically the wider community who may benefit from our basic research.
A key current topic is that of nuclear security. Here our advanced experimental and theoretical techniques may help to address the needs of the security industry. In this regard we are well connected with AWE plc, including collaborative PhD students.
We have recently developed strong links with the National Physical Laboratory, where we enhance their capabilities in radionuclide metrology.
Sustainable energy production is another vital issue for society, and nuclear energy has an important role to play. We have made fundamental advances that lead to a better understanding of decay heat in nuclear reactors. Furthermore, our basic studies of both reaction processes and the structure of unstable nuclei may be important for future nuclear energy technologies.
Cancer diagnosis and treatment is of great importance. Our radiation-detector advances can lead to improved imaging systems, that benefit cancer and other medical treatments.
A key current topic is that of nuclear security. Here our advanced experimental and theoretical techniques may help to address the needs of the security industry. In this regard we are well connected with AWE plc, including collaborative PhD students.
We have recently developed strong links with the National Physical Laboratory, where we enhance their capabilities in radionuclide metrology.
Sustainable energy production is another vital issue for society, and nuclear energy has an important role to play. We have made fundamental advances that lead to a better understanding of decay heat in nuclear reactors. Furthermore, our basic studies of both reaction processes and the structure of unstable nuclei may be important for future nuclear energy technologies.
Cancer diagnosis and treatment is of great importance. Our radiation-detector advances can lead to improved imaging systems, that benefit cancer and other medical treatments.
Organisations
Publications
Dracoulis GD
(2016)
Review of metastable states in heavy nuclei.
in Reports on progress in physics. Physical Society (Great Britain)
Doherty D
(2015)
Nuclear transfer reaction measurements at the ESR-for the investigation of the astrophysical 15 O( a , ? ) 19 Ne reaction
in Physica Scripta
Divaratne D
(2018)
One- and two-neutron removal cross sections of O 24
in Physical Review C
Dinmore M
(2019)
Effects of an induced three-body force in the incident channel of ( d , p ) reactions
in Physical Review C
Dinmore M
(2021)
Three-body optical potentials in ( d , p ) reactions and their influence on indirect study of stellar nucleosynthesis
in Physical Review C
Ding D
(2016)
Pairing in high-density neutron matter including short- and long-range correlations
in Physical Review C
Debenham D
(2016)
Spectroscopy of Kr 70 and isospin symmetry in the T = 1 f p g shell nuclei
in Physical Review C
De Roubin A
(2017)
Nuclear deformation in the A ˜ 100 region: Comparison between new masses and mean-field predictions
in Physical Review C
Datta U
(2016)
Direct experimental evidence for a multiparticle-hole ground state configuration of deformed Mg 33
in Physical Review C
Daniel T
(2017)
? -ray spectroscopy of low-lying excited states and shape competition in Os 194
in Physical Review C
Cáceres L
(2015)
Nuclear structure studies of F 24
in Physical Review C
Cruz S
(2019)
Single-particle structure of neutron-rich Sr isotopes via H 2 ( Sr 94 , 95 , 96 , p ) reactions
in Physical Review C
Crawford, H.L.
(2017)
Unexpected distribution of ?1f7/2 strength in Ca 49
Crawford H
(2017)
Unexpected distribution of ? 1 f 7 / 2 strength in Ca 49
in Physical Review C
Colomer F
(2016)
Extension of the ratio method to low energy
in Physical Review C
Collins SM
(2016)
Half-life determination of the ground state decay of ¹¹¹Ag.
in Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine
Collins SM
(2023)
Determination of the Terbium-152 half-life from mass-separated samples from CERN-ISOLDE and assessment of the radionuclide purity.
in Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine
Collins SM
(2015)
Precise measurements of the absolute ?-ray emission probabilities of (223)Ra and decay progeny in equilibrium.
in Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine
Collins SM
(2015)
Direct measurement of the half-life of (223)Ra.
in Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine
Collins SM
(2018)
Investigation of ?-? coincidence counting using the National Nuclear Array (NANA) as a primary standard.
in Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine
Collins S
(2015)
The half-life of 227Th by direct and indirect measurements
in Applied Radiation and Isotopes
Cipollone A
(2015)
Chiral three-nucleon forces and the evolution of correlations along the oxygen isotopic chain
in Physical Review C
Chrisman D
(2021)
Neutron-unbound states in Ne 31
in Physical Review C
Chishti M
(2023)
Response of the FAst TIMing Array (FATIMA) for DESPEC at FAIR Phase-0
in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Chen ZQ
(2019)
Proton Shell Evolution below ^{132}Sn: First Measurement of Low-Lying ß-Emitting Isomers in ^{123,125}Ag.
in Physical review letters
Chen X
(2016)
Intensity-sensitive and position-resolving cavity for heavy-ion storage rings
in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Chen S
(2019)
Quasifree Neutron Knockout from Ca 54 Corroborates Arising N = 34 Neutron Magic Number
in Physical Review Letters
Charity R
(2020)
Single-nucleon knockout cross sections for reactions producing resonance states at or beyond the drip line
in Physical Review C
Cerizza G
(2016)
Structure of Sn 107 studied through single-neutron knockout reactions
in Physical Review C
Catford W
(2015)
Structure of $^{26}$Na via a Novel Technique Using ($d,p\gamma $) with a Radioactive $^{25}$Na Beam
in Acta Physica Polonica B
Carbone A
(2018)
Microscopic predictions of the nuclear matter liquid-gas phase transition
in Physical Review C
Canavan R
(2020)
Reaction Channel selection techniques and ? - ? fast-timing spectroscopy using the ?-Ball Spectrometer
in Journal of Physics: Conference Series
Canavan R
(2020)
Half-life measurements in Dy 164 , 166 using ? - ? fast-timing spectroscopy with the ? -Ball spectrometer
in Physical Review C
Camacho A
(2019)
Comparative study of the effect of resonances of the weakly bound nuclei Li 6 , 7 on total fusion with light to heavy mass targets
in Physical Review C
Calinescu S
(2016)
Coulomb excitation of Ca 44 and Ar 46
in Physical Review C
Caballero-Folch R
(2016)
First Measurement of Several ß-Delayed Neutron Emitting Isotopes Beyond N=126.
in Physical review letters
Caballero-Folch R
(2018)
First determination of ß -delayed multiple neutron emission beyond A = 100 through direct neutron measurement: The P 2 n value of Sb 136
in Physical Review C
Caballero-Folch R
(2017)
ß -decay half-lives and ß -delayed neutron emission probabilities for several isotopes of Au, Hg, Tl, Pb, and Bi, beyond N = 126
in Physical Review C
Butler P
(2016)
TSR: A storage and cooling ring for HIE-ISOLDE
in Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
Bucurescu D
(2016)
The ROSPHERE ?-ray spectroscopy array
in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Brunet M.
(2020)
208Po populated through EC/ß+decay
in Journal of Physics: Conference Series
Brunet M
(2021)
Competition between allowed and first-forbidden ß decays of At 208 and expansion of the Po 208 level scheme
in Physical Review C
Browne F
(2015)
Lifetime measurements of the first 2 + states in 104,106Zr: Evolution of ground-state deformations
in Physics Letters B
| Description | The grant has funded experimental work at RIKEN, TRIUMF, Argonne, GANIL and other international laboratories and theoretical collaborations with RIKEN, MSU, GSI and other major centres. New isomeric states in exotic nuclei were discovered and much-improved measurements of nuclear astrophysical cross sections were determined. |
| Exploitation Route | Outputs are published in the leading scientific journals and will feed into improved nuclear astrophysics and nuclear structure theories. |
| Sectors | Other |
| URL | http://www.nucleartheory.net/NPG/recent_publications.htm |
| Description | Advancing Nuclear Science via Theory and Experiment |
| Amount | £1,724,621 (GBP) |
| Funding ID | ST/V001108/1 |
| Organisation | Science and Technologies Facilities Council (STFC) |
| Sector | Public |
| Country | United Kingdom |
| Start | 09/2021 |
| End | 03/2025 |
| Description | TENSAR - Theory and Experiment for Nuclear Structure, Astrophysics & Reactions |
| Amount | £2,379,779 (GBP) |
| Funding ID | ST/Y000358/1 |
| Organisation | Science and Technologies Facilities Council (STFC) |
| Sector | Public |
| Country | United Kingdom |
| Start | 08/2024 |
| End | 09/2027 |